WNT5A is a Key Regulator of the Epithelial-Mesenchymal Transition and Cancer Stem Cell Properties in Human Gastric Carcinoma Cells

Abstract

Objective: Direct interaction with cancer-associated fibroblasts triggers WNT5A expression in human gastric carcinoma (GC) cells. In this study, we performed gene transduction experiments to investigate the significance of WNT5A in the GC tumor microenvironment. Methods: Gene transduction (pWNT5A and shWNT5A) was performed in human GC-derived MKN-7 cells. Altered gene expression was examined by RT-PCR and cDNA microarray analysis. Immunohistochemical examination was carried out in human GC tissues. Results: Transduction of exogenous WNT5A expression into MKN-7 cells upregulated genes related to the epithelial-mesenchymal transition (EMT) and cancer stem cells (CSCs), and the pWNT5A transfectant showed high tumorigenicity in vivo. These results were confirmed by knockdown experiments using a lentivirus expressing shWNT5A. A cDNA microarray analysis suggested that depletion of endogenous WNT5A downregulated genes involved in intracellular signaling, chemokine-cytokine interaction and focal adhesion. High levels of WNT5A expression were observed in 66% of GC cases, with significant correlation with histological type. Interestingly, in intestinal-type GCs, WNT5A expression was detected in the periphery of tumor nests. Conclusions: WNT5A regulates the induction of EMT and the maintenance of CSC properties in MKN-7 cells. WNT5A may play an important role in constructing an advantageous tumor microenvironment for the progression and development of human GC.

Diverse Targets of β-Catenin during the Epithelial–Mesenchymal Transition Define Cancer Stem Cells and Predict Disease Relapse

“…To determine whether cancer cells that have undergone EMT and CSCs have similar traits, we induced EMT in serially selected cells (LM and HM1-HM20 cells as described in Supplementary Fig. S1 and Supplementary Information) by exposure to extracellular ligands, including TGFb (19), Wnt3a (20), Wnt5a (21), and BMP4 ( Fig. 1A-C; ref.…”

WNT5A Correlates with Clinicopathological Characteristics in Gastric Cancer: a Meta-Analysis

“…These computational cellular functions in GC cells closely align with our current meta-analysis results, indicating positive association between lymph node metastasis and WNT5A-positivity in GC patients. Recently, WNT5A [19] has been implicating, in GC cells, in inducing the epithelial-mesenchymal transition (EMT), a complex phenomenon involving drastic changes in cellular morphology and various phenotypes [20], largely inhibiting differentiation-related genes. Thus, the association between WNT5A-positivity and advanced cancer stages, in our meta-analysis, may result from WNT5A-driven EMT, resulting in metastasis and other advanced tumor phenotypes.…”

Intratumoral heterogeneity: Clonal cooperation in epithelial-to-mesenchymal transition and metastasis

“…52 Nonetheless, an EMT is highly associated with a gain in metastatic abilities, even when only a small proportion of the tumor has undergone this transition. [53][54][55][56] Thus, EMT may be considered as a largely (although not exclusively) non-genetic contributor to intratumoral heterogeneity. The importance of EMT in the context of a heterogeneous tumor will be discussed in detail within this review.…”

“…92 Importantly, EMP has been shown to occur only within a subpopulation of cells within the primary tumor, thus again demonstrating the heterogeneous nature of tumors. [53][54][55][56] Cancer cells are known to utilize embryonic pathways to promote tumor progression via enhancing properties such as migration, invasion, and neovascularization. 55,93,94 Thus, many of the same molecular players that control developmental EMTs also regulate oncogenic EMTs.…”

“…Although only few cells in a heterogeneous primary tumor may undergo EMT, particularly those at the leading edge of the tumor, [53][54][55][56] it is possible that these few cells may non-cell autonomously increase the potential of surrounding cells to undergo EMT and/or metastasize. Alternatively, it has been proposed that the epithelial tumor cells within a heterogeneous tumor may help to maintain the mesenchymal-like state of tumor cells that have undergone EMT.…”